The present invention relates to spray booths, and in particular to a method and apparatus for removing paint or other coating material from the air exhausted from a spray booth. It is customary to extract air from a paint spray booth and to wash it with a cleaning liquid, generally water, to remove the paint entrained in the exhaust air. Examples of washing systems for the exhaust air from paint spray booths are described in British Patent Specifications Nos. 1165022, 1399805, and 2007542B.
The washing systems described in the above identified patent specifications generally exhibit their best efficiency if a substantially constant volume of air flows therethrough. If the volume of air or the air speed varies, the characteristic performance of the washing systems varies. This can present a problem in that it may be required to vary the volume of air flowing through the paint spray. booth. Clearly if the air flow is so varied the efficiency of the washing systems can be impaired.
In some applications the volume of air flow through the booth must be reduced, and in other applications the volume of air flow can be substantially reduced without adversely affecting the painting operation. As the air supplied to the booth is generally conditioned to be at a predetermined temperature and humidity, any such reduction in the volumes used represents a substantial energy saving.